Charles N Alpers

Mercury in western North America: A synthesis of environmental contamination, fluxes, bioaccumulation, and risk to fish and wildlife

Western North America is a region defined by extreme gradients in geomorphology and climate, which support a diverse array of ecological communities and natural resources. The region also has extreme gradients in mercury (Hg) contamination due to a broad distribution of inorganic Hg sources. These diverse Hg sources and a varied landscape create a unique and complex mosaic of ecological risk from Hg impairment associated with differential methylmercury (MeHg) production and bioaccumulation. Understanding the landscape-scale variation in the magnitude and relative importance of processes associated with Hg transport, methylation, and MeHg bioaccumulation requires a multidisciplinary synthesis that transcends small-scale...

Categories: Publication; Types: Citation

Geochemical data for post-fire surface water, streambed sediment, and soils from areas affected by the 2018 Camp Fire, Butte County, California

During November 2018, the Camp Fire burned more than 150,000 acres in Butte County, California. The fire was the deadliest and most destructive in California history, destroying more than 18,000 structures and causing at least 85 fatalities. The U.S. Geological Survey sampled surface water in areas affected by the Camp Fire, plus an unburned control site, during two post-fire sampling events, January 21-23, 2019 and February 28 - March 1, 2019. During each of those two sampling events, surface-water samples were collected at 8 stream locations. These 16 water samples were filtered using filters with multiple pore sizes (1.2 µm, 0.8 µm, 0.45 µm, and 0.22 µm) to evaluate colloid transport of trace elements. The filtrates...

Categories: Data; Tags: Butte County, California, Environmental Health, Geochemistry, Land Use Change, All tags... USGS Science Data Catalog (SDC), Water Quality, boundaries, fires, runoff, soil chemistry, surface water quality, suspended material (water), Fewer tags

Geochemical data including mercury for subsamples of deep cores from the Cache Creek Settling Basin, Yolo County, California

Sediment cores were collected in the Cache Creek Settling Basin (CCSB), Yolo County, California, during October 2011 at 10 locations (borehole sites) and during August 2012 at 5 other locations. Total core depths ranged from approximately 4.6 to 13.7 meters (15 to 45 feet), with penetration to about 9.1 meters (30 feet) at most locations. Detailed subsampling (3-centimeter intervals) was done at total of seven locations: six along an east-west transect in the southern part of the Cache Creek Settling Basin and at one in the northern part of the basin for analyses of total mercury; organic content; and cesium-137, which was used for dating. This data release reports results of the analyses of each subsample of these...

Categories: Data; Tags: Cache Creek Settling Basin, Sacramento River Watershed, Sacramento–San Joaquin River Delta, USGS Science Data Catalog (SDC), Woodland, CA, All tags... Yolo Bypass, Yolo County, basin, cesium, chemical analysis, drilling and coring, environment, field sampling, geochemistry, isotopic analysis, mercury, mercury contamination, none, sediment geochemistry, wetlands, Fewer tags

Comparison of mercury mass loading in streams to atmospheric deposition in watersheds of Western North America: Evidence for non-atmospheric mercury sources

Annual stream loads of mercury (Hg) and inputs of wet and dry atmospheric Hg deposition to the landscape were investigated in watersheds of the Western United States and the Canadian-Alaskan Arctic. Mercury concentration and discharge data from flow gauging stations were used to compute annual mass loads with regression models. Measured wet and modeled dry deposition were compared to annual stream loads to compute ratios of Hg stream load to total Hg atmospheric deposition. Watershed land uses or cover included mining, undeveloped, urbanized, and mixed. Of 27 watersheds that were investigated, 15 had some degree of mining, either of Hg or precious metals (gold or silver), where Hg was used in the amalgamation process....

Categories: Publication; Types: Citation

Geochemical, mineralogical, and grain-size data for deep cores from the Cache Creek Settling Basin and streambed sediments from the Sacramento River watershed

The Cache Creek Settling Basin (CCSB) is a 13.3 km2 levee-bounded sediment retention basin located at the modern terminus of Cache Creek near the eastern boundary of Yolo County, approximately two miles NE of Woodland, California. The Cache Creek Settling Basin was constructed in 1937 by the U.S. Army Corps of Engineers to trap suspended sediment from the upper Cache Creek watershed during high-flow events, with the purpose of preserving the floodway capacity of the Yolo Bypass, a larger leveed floodway located downstream. This dataset includes subsamples from sediment cores and shallow streambank sediment collected from the Sacramento River watershed. Sediment cores were collected in the Cache Creek Settling Basin...

Categories: Data; Tags: Basin, Cache Creek, California, Drilling and Coring, Geochemistry, All tags... Provenance, Sediment Fingerprinting, Sediment Geochemistry, USGS Science Data Catalog (SDC), environment, geoscientificInformation, Fewer tags